What is most likely true regarding a tender and movable breast lump?

A tender and movable breast lump is most likely associated with benign conditions. When a breast lump is tender, it often indicates that there is inflammation, a hormonal influence, or some other benign pathology rather than malignancy. Many benign breast conditions, such as cysts or fibroadenomas, present in this way. Tenderness in a breast lump can also be associated with cyclical changes related to menstrual cycles, further pointing to a non-cancerous process.

While there are distinguishing features for specific types of lumps like fibroadenomas, stating it is "most likely" a fibroadenoma is somewhat presumptive, especially without diagnostic imaging or more clinical information. Similarly, the idea that tender and movable masses are malignant is inconsistent with patterns typically observed in breast lesions, as malignancies are often hard and immovable.

Regarding diagnosing the lump through a routine physical examination, while a skilled clinician may have suspicions based on palpation findings, definitive diagnosis usually requires further investigation such as imaging studies (ultrasound or mammography) and possibly a biopsy to rule out malignancy.

Thus, the assertion that tender and movable breast lumps are typically benign encapsulates the fundamental distinction between benign and malignant breast conditions.